Apparatus and method for testing magnetic disk drive components using drive-based parts

Abstract

An apparatus and method for testing a component of a magnetic disk drive in which one or more drive-based components is used in the testing process. Each of the drive-based components is based on a corresponding one of the components of the magnetic disk drive. During testing, the component to be tested and at least one of the drive-based components are selectively engaged.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application claims priority from U.S. Provisional Patent Application Ser. No. 60 / 616,243 filed on Oct. 6, 2004 entitled “APPARATUS FOR TESTING HARD DISK DRIVE COMPONENTS FOR TIMING, READING, WRITING, MOTOR CONTROL AND SERVO POSITIONING USING PRODUCTION PARTS” and from U.S. Provisional Patent Application Ser. No. 60 / 616,244 filed on Oct. 6, 2004 entitled “LIGHTWEIGHT HDD ACTUATOR ARM TO HGA ATTACHMENT DEVICE FOR HDD COMPONENT TESTER,” the entirety of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The present invention relates generally to data storage devices and more specifically, to apparatus and methods for testing components of magnetic disk drives.[0003]Magnetic disk drives are typically composed of components such as read / write heads, actuators, magnetic disks, spindle motors, printed circuit board assemblies and firmware. These components are tested during manufacturing using one or more comp...

AI Technical Summary

Benefits of technology

[0014]A tester constructed in accordance with the present invention provides a number of advantages over conventional component testers because it uses components that are based on the components of an actual magnetic disk drive. First, the tester takes less time and cost to develop because it leverages all of the normal magnetic disk drive development and production activities and tools.

[0015]Second, the tester is less expensive to build because it uses components from or based on those used in production disk drives rather than custom made components.

[0017]Fourth, the tester is capable of testing magnetic disk drives with considerably higher accuracy than conventional testers. The tester is more accurate because it provides a testing environment for components that is much closer to that of an actual disk drive. The use of drive-based components allows the tester to perform high-precision, high-bandwidth track positioning during testing with no long-term position drift.

[0018]Fifth, the tester is capable of testing magnetic disk drives with higher TPI densities than conventional testers. This is partly because the tester uses a voice coil motor (VCM)-based actuator that is similar to the actuator of a disk drive. Like the disk drive actuator, the actuator used in the tester is very light, highly optimized and uses a high-bandwidth track-following servo. This allows the tester to track higher TPI and follow higher frequency TMR than conventional testers.

Problems solved by technology

However, the use of conventional component testing machines to test drive components is very costly due to their complicated electrical and mechanical designs.

Conventional testers typically have used expensive precision, custom-made components such as mechanical positioning stages, stepper motors, discrete channels, air-bearing spindle motors and motor plate mechanics.

In addition, conventional testers have been typically designed with little consideration of the disk drive environment.

Thus, conventional testers did not test components in an environment similar to that of an actual disk drive.

As a result, the correlation between the analog test measurements of components obtained with conventional testers and their actual performance in disk drives has been relatively low.

This low correlation resulted in relatively high levels of over-rejects and false acceptance of components.

Another disadvantage of conventional testers is that they relied on mechanical positioners to place the head on the written track instead of using a servo control loop.

This limited the track control or tracks per inch (TPI) capabilities of these testers.

Further, the positioners were not be able to support track-following of high-frequency track misregistration (TMR) because of the low bandwidth inherent to their large mass and size.

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